BUTLER TWP — Medical helicopters flew two women with moderate to serious injuries to Pittsburgh hospitals following a head-on crash in the township late Thursday night, police said. Volunteer firefighters from South Butler and Lyndora had to rescue both drivers, Brandi Denardo, 30, of Ford City, Armstrong County, and Karen Walzer-Kuhn, 39, of Butler, who were trapped in their wrecked cars in the 100 block of Freeport Road. Denardo possibly suffered two broken legs and a broken arm as well as head and stomach injuries, according to Butler Township police. Walzer-Kuhn may have suffered chest and other internal injuries. The collision happened about 10:25 p.m. when Denardo’s eastbound Ford Escort crossed the double yellow line and traveled into the path of Walzer-Kuhn’s westbound Suzuki Kizashi. Investigators did not know immediately what caused Denardo to lose control of her car. Denardo and Walzer-Kuhn were flown to UPMC Presbyterian hospital and Allegheny General Hospital, respectively. Their conditions were not known this morning.